Distraction osteogenesis is a technique where bone is lengthened by slowly pulling apart the fragments of a surgically cut bone. New bone forms in the gap created. It has advantages over orthognathic surgery like being safer, decreasing hospitalization time, and allowing treatment at a younger age as it regenerates both bone and soft tissues. There are different types including monofocal, bifocal, and trifocal distraction used for various bone defects. Distraction is done in phases including latency, distraction, consolidation, and retention using both internal and external distraction devices. It is used to treat conditions like jaw hypoplasia, asymmetry, and defects from tumors or trauma.

1. DISTRACTION OSTEOGENESIS
DR SAGAR

2. Definition : -
 DO is the technique of biological process of bone
lengthening in which osteotomized bone is moved a
part by slow continuous incremental distraction force
and there is neobone regenerate between the two
separate bony ends.

3.  Along with new bone formation there is regeneration of soft
tissues which includes skin, mucosa, muscle and neurovascualr
tissues .
 Soft tissue regeneration is known as distraction histiogenesis.

4. Distraction osteogenesis over orthognathic surgery
 Pediatric obstructive sleep apnea
 Transverse skeletal discrepancy ( without extraction Or proximal
stripping)
 Segmemtal defects
 Irriradiated Cases

5. Advantages of DO over orthognathic
surgery : -
• Safer surgical technique .
• Decreases the length of hospitalisation.
• Can be done at a younger age
• It not only does the bone grow but also associated
soft tissues also grow i.e., muscles,mucosa, skin etc.

6. Types of DO : -
Monofocal distraction : -
 After surgical Osteotomy a distraction gap is created
between two bony ends
 This is conventional approach for lengthening of bones eg :
mandible hypoplasia .
Bifocal distraction : -
 In this type, a continuity bony defect in a bone is managed
by filling the defect with moving a piece of bone from one
end of the defect.
 This moving segment of bone is called transport disk.
 This approach is used for mandibular reconstruction after
tumor ablation.

7. Trifocal distraction : -
 Two transport disks are moved from two sides of
bony defect, until these meet in the centre.
 This technique is used for reconstruction of mid-line
mandibukar defect after tumor removal.

9. Devices : -
 Device for DO used is known as Distractor .
Classification :
Depending on the relation with skin surface :
 Internal devices
 External devices
Depending upon type of anchoring tissues :
 Tooth born
 Bone born
 Hybrid
Depending on the vector / direction : -
 Unidirectional / Bidirectional
 Multivector / multidirectional

10. Depending upon the purpose and site of distraction :
 Maxillary distractors
 Mandibukat distractors
 Alveolar distractors
283A to D (A) showing extemal (30)
Extemal Distraction System KLS
Martin Group); (B) Internal distraction
device [Submerged intraoral device
for mandibular lengthening): (C)
Tooth-bome Hyrax device for
midsymphysis regios (D) Bone-bome
external distraction device (Mutivector
distractor)

11. 28.4A to C: (A) Unidirectional mandibular distraction device and (B) bidirectional mandible
distraction device, which allows two independent sites of distraction (C) Multivector device, in
which trajectory of regenerate bone formation can be manipulated during the distraction process
Linear distraction (sagittal plane), anguiar distraction (vertical plane), transverse distraction
(coronal plane)

12. (A) Rigid external distractor B. Mandible mutidirectional external distraction device
(A) Submerged intraoral device for mandibular lengthening; and (B) semi-buried alveolar distraction
device

13. Indications : -
Mandibular procedures
 1. Hemifacial microsomia
 2. Bilateral mandibular hypoplasia
 3. Syndromic conditions such as Pierre Robin's syndrome.Goldenhar
syndrome etc.
 4. TMJ ankylosis leading to bird face deformity
 5. Traumatic injuries to the mandible or pathologies resulting in
mandibular deficiency
 6. Transverse deficiency of the mandible.
Maxillary procedure
 1. Maxillary deficiency due to presence of cleft lip/palate
 2. Severe midfacial deficiency
 3. Palatal expansion

14. Craniofacial procedures
 1. Apert's syndrome
 2. Frontofacial advancement
 3. Crouzon's syndrome
Alveolar augmentation in the upper and lower atrophic ridges may be done
to develop adequate bone for the placement of implants

15. Pathophysiology : -
 There have been four identifiable stages of mature bone formation.
Stage 1: Stage of fibrous tissue: in this stage the region between the cut bone segments consists
of fibrous tissue. Histologically, this is composed of longitudinally oriented spindle shaped
fibroblasts contained within a mesenchymal matrix of undifferentiated cells.
Stage 2: Stage of extending bone formation: A slender trabecular pattern of bone is observed
along the bony edges towards the fibrous tissue. Early bone formation is seen to advance from
the bony edges along thStagee collagen fibres. The osteoblasts along these early bone spicules
lay down the bone matrix.Blood histochemical investigations will reveal an in creased level of
alkaline phosphatase, pyruvic acid and lactic acid.
Stage 3: Stage of bone remodeling: There are advancing fields of bone resorption and
apposition. There is increase in the number of osteoclasts.
Stage 4: Stage of mature bone formation: Early areas of compact cortical bone are seen to form
close to the mature bone of the non-distracted areas. This bone is less longitu dinally oriented
and resembles the normal bone architecture
By around 8 months the newly formed bone achieves almost 90% of the bony architecture. The
bone then responds to the functional loads applied to it.

16. Phases of DO :
Bone cut / osteotomy :
 A surgical fracture is created in the planned site in the bone
 Blood supply should be preserved
 At the end of osteotomy distraction device is attached to the bone


17. Latency :
 After osteotomy it is advisable to retain the bone in position with the
device for a period around 5-7 days ( period of latency)
 This is done to allow formation of an adequate fibrovasculat bridge
between bony ends of osteotomy
 In younger patients the latency period may be shortened to 1-2 days

18. Distraction phase : - Rate :
 Amount of separation to be achieved between the osteotomised bone
ends per day
 The tensile stress that is applied when the bone ends are separated by 1
mm per day creates the best regenerated bone.
 For younger children since the bone formation may be faster, the rate
be in creased to 1.5-2.0 mm per day.
 If the bone segments are advanced more than this, the blood supply to
the regenerated bone is compromised.
 Also the vascular supply of the over lying and surrounding soft tissues
compromised and leads to necrosis.
 For patients with compromised blood supply such as in case of radiation
therapy to the jaws, the rate of distraction per day is decreased to 0.5-1.0
mm per day.

19. Rhythm :
 Number of times the distraction force is applied to the device in a day
 Ideally force is applied continuously thought the day, but clinically the
force is applied Twice a day
 Each time 0.5mm is done to make 1mm a day ( rhythm of distraction)
 If the patient experiences pain during the process, rhythm is altered i.e.,
0.25mm in four increments

20. Consolidation Phase : -
 Once satisfactory Amount of distraction has taken place,
the regenerate is stabilized in position for complete
ossification
 Distraction device is held in neutral position for a period of
6 weeks
 If the device is removed prematurely, chances of relapse are
more as the bone has not ossified completely.

21. Retention phase :
 After a period of consolidation, the distraction device is
removed and the jaws are stabilized with orthodontic
appliance Or occlusal splints.
 Elastic traction may be applied in children.

23. Principles of DO ( Ilizarov 1950 s)
 Osteotomy with blood supply preserved
 Latency : 5-7 days formation of fibrovascular bridge
 Rate – distraction 1mm/ day
 Consolidation phase – Neutral position 4-6 weeks
 Retention phase – device removed, jaw stabilised

24. Fig 28.7A: Patient with severe
mandible hypoplasia treated with
extemal ollatera unidirectional
distraction osteogenesis. Large
malocclusion was created by the
seletal movement. Orthodontic
treatment was used to correct
malocclusion. First row pictums
preoperative facial photos: second
row-1 year 3 months post distraction
photos; third row 4 years
postdistraction photos

25. intraoral dental occlusion
photos of the same patient in
Figure 28.7A First vertical row-
pretreatment photographs
showing severe positive overet
due to severe retrognathia:
second row-post distraction,
and third row-posforthodontic
treatment photographs
showing corection of
nitrognathia and malocclusion

26. Patient with hypoplastic maxila due to
unilateral cell lip and palate deformity, treated
by distraction at Le fort level Post-treatment
photographs showing correction of maxillary
hypoplasia stable result after 4 years

27. Mandible transverse deficiency can be corrected by osteotomy in
symphysis region of mandible and placement of tooth bom mandibular
distraction device Space gained with distraction was itized to align
crowded teeth orthodontically

28. Patient with hemifacial microsomia in Oct.
2009; (B) Patient's photographs after two
years watching growth: (C) Palient treated
with unilateral distraction of the mandible
(D) Post-treatment and postdistraction photographs; and
(E) Orthopantomograms show correction of mandible
hypoplasia. She will need second phase of orthodontic
treatment after growth completion

29. A 54-year-old patient with plexiform
ameloblastoma in anterior mandible
region was treated with excision of
the lesion and creating a continuity
defect from right second premolar
to Tell first premoar. The transport
disks were created on both sides,
with right side containing first and
second moarteth, while left side of
the transport disk contained second
premolar tooth. Transport
distraction was done for 40 days, at
the rate of 0.75 mm/day. After
consolidation period of 4 months,
the distraction device was removed
Prosthetic rehabilitation was done by
tooth supported overdenture

30. A case of Crouzon's syndrome with
proptosis, and midface retrusion and
difficulty in broathing (severe costructive
sleep apnee) He had undergone fronto-
orbital advancement in 2001 Tracheostomy
was done in 2013 due to obstructive sleep
apnea and severe chest infection. Le fort II
ostectomy was done and distraction was
canied out with RED device

31. (A) A 12-year-old boy had unilateral mandibular distraction for correction of
facial asymmetry due to hypoplastic eft mandible, and (D) Reappearance of
asymmetry after 15 months due to active growth of contralateral condyle